Engine.



Patnaad luly 30, 190|.

E. E. HEDFIELD.

ENGINE.

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Patented July 3o, 190|.

E. E. REDFIELIL E N G I N E.

(Application tiled Har. 9, 1901.)

2 Shank-Sheet 2.

(No Model.)

UNITED STATES PATENT OEEICE.

EDWARD E. REDFIELD, OF GRANTS PASS, OREGON.

ENGINE.

SPECIFlCATION forming part of Letters Patent No. 679,637, dated July 30, 1901.

Application filed March 9, 1901. Serial No. 50,462. (No model.)

T all wtont t may concern.-

Beit known that I, EDWARD E. REDFIELD, a citizen of the United States, and a resident of Grants Pass, in the county of Josephine and State of Oregon, have invented new and useful Improvements in Engines, of which the following is a full, clear, and exact description.

This invention relates to an engine to be driven by motive iiuid of any sort and characterized by a reciprocating piston and certain peculiar valve mechanism controlling the motive iiuid. The engine is especially adapt ed to operate drag-saws but it should be understood, however, that the engine is useful in other connections, as will explain themselves to persons skilled in the art.

This specification is a specific description of one form of the invention, while the claims are definitions of the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this speciiication, in which similar characters of reference indicate corresponding parts in all the views.

Figure lis a sectional view of the invention with parts broken away. Fig. 2 is a similar view showing the parts in different positions. Fig. 3 is a sectional view showing the parts in still another position. Fig. 4 is a plan View of the engine. Fig. 5 is a side view of the tu bular valve, showing it detached from the rest of the apparatus; and Fig. 6 is an enlarged detail side View of the valve-operating gear., showing the movements thereof.

a indicates the cylinder' of theen gine, which may be of any suitable length.

`t) indicates the piston, andfb the rod. The rod is tted to move through a gland a on the cylinder, and it carries a cross-head b2, having two studs h3 and b4. The studb is fast on the cross-head, and the stud bL1 is mounted to slide therein and is engaged by a spring h5.

ln using the invention in connection with a drag-saw the saw is pivoted -to the studs b3 and h4, and the spring b5 in yielding permits the saw to be rocked slightly, as is essential to the proper operation of the drag-saw. Attached n'ies a tappeto at its rear end, such tappet comprising an inclined front surface cia and a plane top surface c3. A tappet c4, similar in form to the tappet c', is carried b v the upper end of the cross-head b2. The tappets c and c4 project in opposite directions--that is to say, their inclined front surfaces point toward each other-and these tappets, movingin time with the piston Z) of the engine, serve to 0p- `crate the valve, as will be fully described hereinafter.

Boxes a2 and a3 are formed, respectively, at the ends of the cylinder a and carry the tubular slide valve d, this valve extending throughout the length of the cylinder and parallel therewith. Pivoted on the stuffing-box a of the cylinder a is a rocker e,which extends upward and has two arms e' in the form of a fork at its upper end. The arms have their extremities e2 bent transversely in opposite directions, such extremities being respectively in line with the tappets c' and c4. The rocker e is connected by a link c3 with the slide-valve d. As the parts b, b2, and c reciprocate the tappets c' and c4 alternately engage the extremities c2 of the arms e' of the rocker e and throw the rocker from the position shown by full lines in Fig. 6 to that shown by dotted lines in said iigure, and vice versa. When the inclined extremities c2 strike the extremity of the arm e', it th rows the rocker slowly toward its opposite position, and when the end of the arm e" rides up over the `curved end c2 of the 1 tappet and reaches the top surface c3 thereof i the rocker will have been thrown to its opposite position. The tappet then passes under the arm of the rocker, sliding the top surface o3 along the same, and thus holding the rocker in the position to which it was thrown and preventing any idle movement of the rocker immediately subsequent to the assumption of its new position. The rear end of the valverod c has a downwardly-projected lug c5,which slides loosely on the tubular valve d without influencing the movement thereof. The front end of the rod c is held slidably in a box a, forming an extension of the box a3. The valve tl is provided with attached collars d', adapted, respectively, to engage the boxes a2 and as, so as to limit the movement of the valve.

The motive fluid is led to the en gine through dis open.

a supply-pipe f, and this pipe communicates with the interior of the box a2 through a port f'. The tubular valve has its rear end formed with three ports, respectively designated 612,7' d3, and d4. Aplug or` stopper d5 is fitted inthe tubularvalve d between the ports cl3 and d4. The rear end of the tubular valve The front end of the tubular valve d is formed with two ports d6 and d?, between which is arranged a plug or stopper d8. The .front end ot' the valve is also open. A fluidpassage a4 is formed at the rear end of the cylinder, the passage leading from said end ofthe cylinder to and communicating with the interior of the box a2. A duid-port a5 isl formed at the front end of the cylinder, this port leading from the cylinder tol and communicating with the interior ot' the boxes. Assuming that the parts are in the position shown in Fig. l, in which it will bessen that the piston b is at the limit of its rearward stroke and that the port d2 is in registry with the portf, the port d3 in registry with the passage d4, and the port Z7 in registry with the passage a5, the motive fluid passing from the pipe f will enter the tubular valve d through the port b2 and will pass ont of the same into the cylinder and act against the rear side of the piston through the port d3 and passage a4. .The exhauststeam will pass through the passage a5 and port d7 and out the open front end of the valve d. The rod c and attached parts move with the piston. Fig. y2 shows the piston at approximately the middle of its stroke, the valve devices being in the same position as in Fig. l. Fig. 3 shows the position ofthe parts when the end of the stroke has been reached and immediately upon the return or rearward movement of the piston. In this view the rocker e is indicated in dotted lines as being thrown to the position opposite that in which it is thrown in Eigs. l and 2, and when the parts are soy disposed the position of the valve d will have been changed, so as to place the port d6 in registry with the passage d5, the port d3 in registry vwith the port f', and the port d'1 in registry with the passage a4. The live steam no'w passes into the tubular valve by way of the port dfand traversing the length of the valve it passes into the front end of the cylinder through the port d6 and passage d5,

driving the piston in the direction of the arrangement of the engine will be apparent to persons skilled in the'art.

Various changes lin the form, proportions, and minor details of my invention may be resorted to without departing from the spirit and scope of my invention. Hence I consider myself entitled to all lsuch variations as may rlie within the scope of my claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. An engine having a cylinder, boxes arranged at the end portions thereof and communicating with the cylinder, atubular valve having its end portions mounted in the boxes, the valve being in communication with a source of fluid-supply and having at each end two ports separated from each other by a plug or stopper fitted in the valve andthe ends of the tubular valve being open, and a gear for operating the valve.

2. An engine havinga valve-gear comprising a' rocker connected with the valve to actuate it, the rocker having a forked upper end, the arms of which are turned laterally in opposite directions, and two tappets moving in unison toward and from the rocker and ar- .ranged respectively to engage said laterallybent ends of the rocker-arms, to throw the rocker.

' 3. An engine having a valve-gear, comprising a rocker connected with the valve, and two tappets arranged at opposite sides of the rocker and moving in unison toward and from the same to throw the rocker back and forth.

4. An engine having a cylinder with steampassages at its ends, a tubular valve having communication with the steam-supply and having two ports in each end portion, a closure tted between cach pair of ports,and a gear for reciprocally driving the valve.

5. An engine, comprising a 4cylinder with steam-passages at its ends, a tubular valve extending parallel with the cylinder and commanding the steam-passages thereof, a rod connected with the piston and arranged to slide parallel with the cylinder, and a rocker connected with the valve and engaged by parts on the rod,whereby to operate the valve.

6. An engine,having a cylinder with steampassages at its ends, a tubular valve having communication with the steam-supply and having feed-ports coacting with the steampassages of the cylinder, the tubular valve having exhaust-ports also coacting with the steam -passages, and means carried in the valve for separating the feed and exhaust passages.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

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